Razib already did the
href="http://scienceblogs.com/gnxp/2008/11/fear_of_a_black_president_miss.php">definitive
post of voting trends in the South,
looking especially at the influence of skin color.
Now, we see there is a peculiar correlation: those areas that had the
highest cotton production before the Civil War are the areas in which
Obama did especially well.
In the map below, each black dot represents 2,000 bales of cotton
produced in 1860. The counties shown in blue had a majority
of voters who voted for Obama; red for McCain. The darkness
of the hue indicates the strength of the majority.
I found the map
href="http://strangemaps.wordpress.com/2008/11/15/330-from-pickin-cotton-to-pickin-presidents/">here;
they got the original two maps from
href="http://www.pin-the-tail.com/?p=1056">here,
and merged them. Now compare to the
href="http://www.nytimes.com/interactive/2008/11/05/us/politics/20081104_ELECTION_RECAP.html">NYT
map showing which
counties voted more Republican in 2008 than in 2004:
The areas that were more strongly Republican are, predominantly, the
areas that are north and west of the areas that went for Obama in the
first map.